[v5.15] possible deadlock in team_del_slave

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syzbot

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Apr 15, 2023, 3:03:50 AM4/15/23
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Hello,

syzbot found the following issue on:

HEAD commit: 4fdad925aa1a Linux 5.15.107
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1459695bc80000
kernel config: https://syzkaller.appspot.com/x/.config?x=d9bc1b227ee6c412
dashboard link: https://syzkaller.appspot.com/bug?extid=08d8ab0dfd5994ad695e
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6a7f3b0f6a27/disk-4fdad925.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/db34418039b7/vmlinux-4fdad925.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4e96525a950a/bzImage-4fdad925.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+08d8ab...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
5.15.107-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.1/4480 is trying to acquire lock:
ffff88802bc74cf8 (team->team_lock_key#4){+.+.}-{3:3}, at: team_del_slave+0x2e/0x1f0 drivers/net/team/team.c:1993

but task is already holding lock:
ffff88807b538628 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: nl80211_del_interface+0x127/0x370 net/wireless/nl80211.c:4103

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&rdev->wiphy.mtx){+.+.}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
wiphy_lock include/net/cfg80211.h:5311 [inline]
ieee80211_open+0x13a/0x1f0 net/mac80211/iface.c:361
__dev_open+0x36f/0x500 net/core/dev.c:1486
dev_open+0xa9/0x260 net/core/dev.c:1522
team_port_add drivers/net/team/team.c:1210 [inline]
team_add_slave+0x916/0x2760 drivers/net/team/team.c:1979
do_set_master net/core/rtnetlink.c:2523 [inline]
do_setlink+0xe71/0x3af0 net/core/rtnetlink.c:2728
__rtnl_newlink net/core/rtnetlink.c:3395 [inline]
rtnl_newlink+0x177d/0x2060 net/core/rtnetlink.c:3510
rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5587
netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2533
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356
netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1952
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg net/socket.c:724 [inline]
____sys_sendmsg+0x59e/0x8f0 net/socket.c:2412
___sys_sendmsg+0x252/0x2e0 net/socket.c:2466
__sys_sendmsg net/socket.c:2495 [inline]
__do_sys_sendmsg net/socket.c:2504 [inline]
__se_sys_sendmsg+0x19a/0x260 net/socket.c:2502
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #0 (team->team_lock_key#4){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
team_del_slave+0x2e/0x1f0 drivers/net/team/team.c:1993
team_device_event+0x267/0x490 drivers/net/team/team.c:3016
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:1998 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2010 [inline]
call_netdevice_notifiers net/core/dev.c:2024 [inline]
unregister_netdevice_many+0xf1b/0x18f0 net/core/dev.c:11065
unregister_netdevice_queue+0x2e6/0x350 net/core/dev.c:10998
unregister_netdevice include/linux/netdevice.h:3012 [inline]
_cfg80211_unregister_wdev+0x181/0x510 net/wireless/core.c:1127
ieee80211_if_remove+0x1cc/0x2c0 net/mac80211/iface.c:2090
ieee80211_del_iface+0x15/0x20 net/mac80211/cfg.c:145
rdev_del_virtual_intf net/wireless/rdev-ops.h:57 [inline]
nl80211_del_interface+0x1f5/0x370 net/wireless/nl80211.c:4105
genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
genl_rcv_msg+0xfbd/0x14a0 net/netlink/genetlink.c:792
netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2533
genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356
netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1952
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg net/socket.c:724 [inline]
____sys_sendmsg+0x59e/0x8f0 net/socket.c:2412
___sys_sendmsg+0x252/0x2e0 net/socket.c:2466
__sys_sendmsg net/socket.c:2495 [inline]
__do_sys_sendmsg net/socket.c:2504 [inline]
__se_sys_sendmsg+0x19a/0x260 net/socket.c:2502
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&rdev->wiphy.mtx);
lock(team->team_lock_key#4);
lock(&rdev->wiphy.mtx);
lock(team->team_lock_key#4);

*** DEADLOCK ***

3 locks held by syz-executor.1/4480:
#0: ffffffff8da332b0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802
#1: ffffffff8d9d3ca8 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x28/0x540 net/wireless/nl80211.c:14959
#2: ffff88807b538628 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: nl80211_del_interface+0x127/0x370 net/wireless/nl80211.c:4103

stack backtrace:
CPU: 0 PID: 4480 Comm: syz-executor.1 Not tainted 5.15.107-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1646/0x58b0 kernel/locking/lockdep.c:3787
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
team_del_slave+0x2e/0x1f0 drivers/net/team/team.c:1993
team_device_event+0x267/0x490 drivers/net/team/team.c:3016
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:1998 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2010 [inline]
call_netdevice_notifiers net/core/dev.c:2024 [inline]
unregister_netdevice_many+0xf1b/0x18f0 net/core/dev.c:11065
unregister_netdevice_queue+0x2e6/0x350 net/core/dev.c:10998
unregister_netdevice include/linux/netdevice.h:3012 [inline]
_cfg80211_unregister_wdev+0x181/0x510 net/wireless/core.c:1127
ieee80211_if_remove+0x1cc/0x2c0 net/mac80211/iface.c:2090
ieee80211_del_iface+0x15/0x20 net/mac80211/cfg.c:145
rdev_del_virtual_intf net/wireless/rdev-ops.h:57 [inline]
nl80211_del_interface+0x1f5/0x370 net/wireless/nl80211.c:4105
genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
genl_rcv_msg+0xfbd/0x14a0 net/netlink/genetlink.c:792
netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2533
genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356
netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1952
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg net/socket.c:724 [inline]
____sys_sendmsg+0x59e/0x8f0 net/socket.c:2412
___sys_sendmsg+0x252/0x2e0 net/socket.c:2466
__sys_sendmsg net/socket.c:2495 [inline]
__do_sys_sendmsg net/socket.c:2504 [inline]
__se_sys_sendmsg+0x19a/0x260 net/socket.c:2502
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f18bf9aa169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f18bdf1c168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f18bfac9f80 RCX: 00007f18bf9aa169
RDX: 0000000000000000 RSI: 0000000020000600 RDI: 0000000000000003
RBP: 00007f18bfa05ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd004b928f R14: 00007f18bdf1c300 R15: 0000000000022000
</TASK>
team0: Port device wlan0 removed


---
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syzbot

unread,
Aug 13, 2023, 3:03:57 AM8/13/23
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
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